Part II. — Stichodactylince and Zoanthece. 175 



Actinoporus elegans, Duchassaing. 

 (PL x., %. 9 ; PI. xi., fig. 8 ; PL xiii., figs. 2, 6; PL xiv., fig. 3 ; PL xv., fig. 2.) 



Actinoporus elegans, . . . Duchassaing, 1850, p. 10; Milne-Edwards, 1857, 



p. 277; Duchassaing and Michelotti, 1860, 

 p. 46, pi. vii., fig. 6; 1866, p. 132. 



Aureliania elegans, . . . Andres, 1883, p. 497. 



The base is buried to a considerable depth in sand and gravel, and is thin- 

 walled, the lines of attachment of the mesenteries showing through ; towards the 

 margin it may also be deeply grooved in correspondence with the mesenteries. In 

 diameter it is scarcely larger than the column. 



The column is greatly elongated, cylindrical, smooth, strongly ridged and 

 grooved above and below, and, but for a thin opaque whiteness, nearly transparent. 

 A row of circular transparent verrucse occurs on all the ridges, rendered very 

 evident by the absence of the opaque whiteness, they appear more like vesicles 

 in the preserved polyp. Along some ridges the transparent discs are not 

 so perfectly circular as on others, and they may be in more than a single series, or 

 even become contiguous. In the preserved condition the column is coarsely 

 wrinkled transversely, less so longitudinally, and is of greater diameter above than 

 below. A smooth, deep fossa exists between the marginal verrucas and the 

 tentacles. 



The disc is flat or partly folded, not much broader than the column, and made 

 up of forty-eight long, radiating, triangular areas, separated one from the other by 

 deep, smooth sulci. A small, central area is naked and smooth. The areas bear 

 extremely short, capitate or spheroidal tentacles, which seem to be little more 

 than small vesicular outgrowths of the disc. These are often bifurcated or lobed, 

 and extend from the fossa to near the mouth, increasing a little in size from within 

 outwards. Odd smaller vesicles occur among the larger. Over the greater part of 

 the disc the tentacles arrange themselves approximately in two rows along each 

 side of a radiating area, but they communicate in an irregular manner with the 

 ccelenteron. Towards the centre of the disc they form but a single row along the 

 middle of the radiations. Some rows extend slightly more centrally than others, 

 but no serial arrangement can be distinguished. 



As a whole the tentacles give to the disc, both in the living and preserved 

 condition, a finely beaded appearance ; peripherally they completely hide its 

 actual surface, but are more distant towards the middle. They possess apparently 

 no power of retraction, and communicate with both the endocceles and exocceles, 



2C2 



